Painful "gluten rashes" might not be forever

NEW YORK (Reuters Health) - A small percentage of people with a painful, blistering skin disease may eventually go into remission, saving them from medication and a strict diet, a new study reports.

"A 'lifelong' disease may not be lifelong," study author Dr. Stephen Katz at the National Institutes of Health told Reuters Health.

The condition is dermatitis herpetiformis, in which people develop painful blisters, itching, and burning on primarily the elbows, knees, and buttocks. It is an autoimmune condition associated with celiac disease, in which eating gluten -- a type of protein found in wheat, barley, and rye -- causes the body's immune system to attack and damage the small intestine.

An estimated 1 in 133 people has celiac disease in the U.S. A small percentage of those - a few percent, Katz estimated - will develop dermatitis herpetiformis, diagnosed by a skin biopsy that looks for certain types of proteins.

People with dermatitis herpetiformis are typically advised to take drugs (most commonly, dapsone) and follow a strict gluten-free diet, in order to keep their symptoms at bay. But the new study found that, among 86 people with dermatitis herpetiformis, 10 never saw their symptoms return after stopping medication and resuming a normal diet.

So even though people with celiac disease are supposed to stay gluten-free indefinitely, for those with dermatitis herpetiformis who don't have intestinal symptoms, it makes sense to stop the diet and see if they feel okay, Katz said.

Medications to treat dermatitis herpetiformis can work well, he said, but they come with potential side effects, such as a decrease in blood cells, so patients should always take the smallest dose they need, and ideally stop medication altogether.

In his practice, Katz tries to slowly wean his patients off the medicine entirely over a multi-year period and advises them to eat small amounts of gluten, and see if their symptoms return.

"I always tell them to cheat a little bit, see if they need the diet," he said. "Because if some patients don't need the medicine, they may no longer need the diet."

In the current study, published in the Archives of Dermatology, one-third of dermatitis herpetiformis patients had once had symptoms of celiac disease - but they were just as likely to go into remission as those with no celiac symptoms.

Unfortunately, there were no obvious differences between the patients who went into remission and those who didn't, Katz noted. "We couldn't make sense of it."

Dr. John Zone, chair of the department of dermatology at the University of Utah, who reviewed the findings for Reuters Health, said the remission rate of 12 percent matches what he's seen in his practice. "I agree with the percentage of people who have spontaneous remission."

There is concern, he added, that people who don't stick with the diet may have a higher risk of lymphoma and other complications. Consequently, Zone suggested that patients with dermatitis herpetiformis who decide to stop the diet have their blood tested occasionally to look for celiac antibodies, even if their skin symptoms never return.

Luckily, a small percentage of them will be able to enjoy a normal diet and a life without dermatitis herpetiformis medication, Zone said -- which is a very good thing. Dermatitis herpetiformis is "probably the most uncomfortable skin disease you can have," he said. "It just itches night and day."

In those fortunate few who go into remission, the immune system has simply changed, and "decided not to react to gluten any longer," he said. "There probably is some molecular mechanism we don't understand yet."